in this section the file size its shows 4.4G for
debian-31r2-i386-binary-1, but when I am downloading it give me 372MB
and for the another file debian-31r2-i386-binary-2 it shows 4.1G but
when I downloads it gives me 127MB.

Better check your internet connection. Most likely yor downloading timed
out and left you with a partial download. Use the check sum given in the
site to see if you have the complete file.

So is this file ok or has to be correct 4 GB? I have doubt just because
of this sizes. And is it according to above MB's then even I can burn on

normal 700MB CD's right?

Wrong. You cannot burn a DVD image on a CD. it wont work.
So what's the meaning of DVD ISO Files? I